Japanese Patent Laid-open Publication No. 2000-82108 (hereinafter referred to as “Patent Document 1”) discloses a method which picks up an image of a card by use of a CCD camera, for example, the card having an identification image (two-dimensional code and the like) attached on front or back side thereof, finds image data of the identification image attached on the card from the image data of the pickup image, and detects identification information of the card from the image data of the identification image thus found.
Evolving from the method as described above, Japanese Patent Laid-open Publication No. 2000-322602 (hereinafter referred to as “Patent Document 2”) discloses an example that displays on a monitor a pickup image including an image of the card, and displays a three-dimensional image of an object associated with the identification information being detected, in such a manner as being superimposed on the image of the card displayed on the monitor. According to this method, it is possible to represent a visual effect by merging real space and virtual space.